[Boost-users] boost function with lambda bind

From: Santosh Joseph (santoshjoseph73_at_[hidden])
Date: 2006-12-10 23:39:15

I'm trying to use a boost function object within a
lambda bind. This is my test program and the commented
line does not compile. What i'm trying to do is
iterate over a container of test_str structs which has
one data  member (a string) and get that string and
insert that string into another string.

#include <string>
#include <set>
#include <vector>
#include <iostream>
#include "boost/lambda/lambda.hpp"
#include "boost/lambda/bind.hpp"
#include <algorithm>
#include "boost/function.hpp"

using namespace std;

struct test_str
{
    test_str(string s): str(s){}
    string str;
};

int main(int argc, char* argv[])
{
   using namespace boost::lambda;
   boost::lambda::placeholder1_type Arg;

   typedef pair<set<string>::iterator,bool>
(set<string>::*INSERT)(const string&);
 
   set<string> str_con;
   INSERT insert_func = &set<string>::insert;
   vector<test_str> v2;
   v2.push_back( test_str("one") );
   v2.push_back( test_str("two") );
   boost::function<string&(test_str&)> f =
bind(&test_str::str, Arg);
   //for_each( v2.begin(), v2.end(), bind(
insert_func, var(str_con), var(f)));
   for_each( v2.begin(), v2.end(), bind( insert_func,
var(str_con), bind(&test_str::str, Arg)));
   return 0;
}

This is part of the error message i get from a
vs2003.net compiler.
Any help would be appreciated.

c:\santosh\tools\boost_1_33_1\boost\lambda\detail\function_adaptors.hpp(250):
error C2664: 'std::pair<_Ty1,_Ty2> (Arg1)' : cannot
convert parameter 1 from 'boost::function<Signature>'
to 'const std::basic_string<_Elem,_Traits,_Ax> '
        with
        [
           
_Ty1=std::_Tree<std::_Tset_traits<std::string,std::less<std::string>,std::allocator<std::string>,false>>::iterator,
            _Ty2=bool,
            Arg1=const std::string &
        ]
        and
        [
            Signature=std::string &(test_str &)
        ]
        and
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]

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